Hum eliminator



W. R. KIEFER HUM ELIMINATOR Feb. 17, 1942.

Filed Dec. 23, 1939 a n g 3. am i g i V l 1 in u 3 31.. u u m j m n I CIC 0 Z V INYENTOR. 181E) L; A ORNEY.

Patented Feb. 17, 1942 UNITED STATES PATENT OFFICE HUM; ELIMINATOR William Ray Kiefer, Rockford, 'lll assignor to j Sundstrand Engineering 00., Rockford, IlL, a corporation'of Illinois i Application December 2 3, 1939, Serial No. 310,686

4 Claims.

The-invention relates generally to the elimination of bum in hydraulic circuits, particularly oil burner circuits, and has as a general'object to provide a new and improved construction accomplishing that result.

A more particular object of the invention is to provide a hum eliminator, adapted for connection in circuit with a pump, having a non-metallic diaphragm disposed to have the intake fluid of the pump flow over one face thereof and the by-pass fluid flow over the other face thereof.

Yet another object is to provide a hum eliminator device having a non-metallic diaphragm secured between two casing sections each section having an inlet and a discharge port and a baille directing the fluid flowing through the sec- 7 tion into contact with and over the face of the diaphragm. v Other objects and advantages will become apparent from the following detailed description, taken in connection with the accompanying drawing, in which:

. nection in a single line fluid system.

While the invention is susceptible of various modifications and alternative constructions, it is shown in the drawing and will be described hereinafter in a preferred embodiment. It is not intended, however, that the invention is to be limited thereby to the specific construction shown, but it is intended to cover all modifications and .alternative constructions falling within the spirit and scope of the invention as defined in the appended claims.

While the principle of this invention may be embodied in various devices, including directly in a pump, it is for purposes of disclosure herein shown as embodied in a separate unit, generally designated 5, and connected in circuit with a fuel pump 6 which may take any conventional oil burner nozzle or the like, and a by-pass return port H! which communicates with a return line I I for returning to the tank or reservoir the excess of fluid pumped over that flowing through the discharge port 9.

As shown herein, the hum eliminator comprises a hollow casing formed of separable and symmetrical sections [2 and I3. Each section hasa bowl shaped portion l4, a semi-cylindrical portion 15 opening to the bowl shaped portion through the bottom thereof and an annular radially outwardly projecting flange [6. The sections l2 and I3 are secured together by any suitable means, such as bolts l1, and clamped between the flanges 16 of the sections is a nonmetallic diaphragm l8 which divides the hum eliminator into two chambers. To adapt the unit 5 for connection in a hydraulic circuit, each section is provided with a pair of ports [9 formed in the ends of the semi-cylindrical portion so as to be disposed opposite one another. One port IQ of the section l2 (the upper one as viewed in Fig. 1). is connected to the suction line 8, while the other port l9 of the section [2 is connected to a continuation 8' of the suction line. Similarly, theupper port I9 of section [3 is connected to the return line H, while the lower port is connected to a continuation ll of the return line.

It is a feature of this invention that the fluid flowing through the hum eliminator device is made to flow over and in contact with the diaphragm l8 in order that the hum may be effectively eliminated from the circuit. Accordingly, each section has an imperforate baffle 20 which is anchored in the cylindrical portion l5 intermediate the ends of the cylindrical portion and disposed in a plane at right angles to a line connecting the ports [9. This bafiie 20, as best seen in Fig. 2, extends the full diameter of the semi-cylindrical portion I5, as well as the full diameter of the bowl shaped portion l4, and projects inwardly from the semi-cylindrical portion toward the diaphragm I8 a substantial distance. As a result, fluid drawn in through the extension 8 of the suction line may not pass directly to the suction line 8, but must flow laterally around the inner edge of the baflle 20 and thus must flow over and in contact with the face of the diaphragm I8. Such flow of the fluid over theface of the diaphragm has resulted in a much'more effective elimination of hum from the circuit than has ever been accomplished before. This is particularly true when the hum eliminator device 5 is so connected, either by connection in the circuit externally of the pump or by incorporation .as a unitary part of the pump, that the suction or intake fluid is in one of the chambers formed by the diaphragm while the by-pass return fluid is in the other chamber formed by the diaphragm l8.

While the invention herein disclosed is preferably utilized in a circuit having a suction and a by-pass return line, it may readily be adapted for use in a single line system, that is, one having no return line. To adapt the invention for such use, the ports IQ of one of the sections are simply plugged to form an air chamber, while the ports l9 of the other section are connected in the suction or intake line to the pump the same as above described. Fig. 3 shows the unit 5 adapted for such use with a single line circuit and shows the section l3 having its ports I9 closed by plugs 2| screw threaded into the ports,

It is believed apparent from the foregoing that I have perfected a vastly improved means or device for eliminating hum in hydraulic circuits, particularly oil burner circuits in which such hum is commonly prevalent and most obnoxious. My hum eliminator means has been found to be particularly effective and this is believed in large part due to the construction wherein'the'fiuid in the circuit actually flows through the hum eliminator device and, more particularly, flows over and in contact with the diaphragm incorporated in the device. In addition to being unusually effective in the elimination of hum,-my'inventionhas the additional advantages that it may readily be incorporated in existing circuits without difiiculty, and is adaptable for use. both with a circuit having a b y-pass return line or with circuits not having such by-pass return line.

I claim as myinvention:

1. A fluid circuit comprising, in combination, a pump having an inlet port, a discharge port and a by-pass port, an intake line connected to the intake port of said pump, a by-pass repump, and a-hum eliminator device comprising a hollow casing, a non-metallic diaphragm dividing said casing into two chambers, one of the turn line connected to the by-pass port of said chambers being connected in the intake line and the other of said chambers being connected in the by-pass line to have the fluid flowing in the lines flow through the chambers.

2. In a fluid circuit, a pump having an intake port, a discharge port and a by-pass return port, and means for eliminating hum including a non-metallic diaphragm, said means being connected in the intake side of said pump to have the intake fluid flow over one face of said diaphragm, and connected in the by-pass return side of the pump to have the by-pass fluid flow over the opposite face of the diaphragm.

3. A hum eliminator device for use in a fluid circuit having a pump with an intake port, a discharge port, and a by-pass return port including a non-metallic diaphragm forming a yieldab-le common wall for a pair of chambers, the device being connected in the circuit to have the intake fluid flow over one face of said diaphragm, and theYb y-pass return fluid flow over the other-faceof said diaphragm.

4. A hum eliminator device for use in a fluid circuit having a pump with an intake port, a discharge port and a by-pass return port, a suction line connected to the intake port, and a bypass return'line connected to the return port comprising a casing'composed of separable sections, a non-metallic diaphragm secured between said sections to divide the casing into two separate-chambers, apair of ports opening to one of said chambers for connection of said chamber in the suction line of the circuit, a pair of ports opening to the other of said chambers for connection of said other chamber in the return line of the circuit, and a bafile in each of the sections of said casing disposed between said ports and extending towards said diaphragm but short thereof to cause the fluid flowing through the chamber to pass over and in contact with the fact of said diaphragm.

WILLIAM RAY KIEFER. 

